Voltage transients caused by load changes or unstable load conditions can be difficult to correct quickly enough to prevent over-voltage conditions on the power supply output.
For example, unstable load conditions causing oscillations in supply voltage tend to occur when a negative impendence load is supplied in power by a conventional regulated power supply system. This is because negative impendence characteristics, in contrast with conventional resistive loads and inductive loads, generate current variations which are 180 degrees out of phase with supply voltage variations. Hence, for a negative impedance load supplied with constant power, a slight increase in output voltage tends to decrease the current absorbed by the load, which in turn tends to cause the load voltage to rise even further leading to an unstable condition which may damage the power supply system and its loads.
There is thus a need for a regulated power supply system which exhibits an improved response to transient load changes or unstable load conditions.